<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>赋值运算符</title>
    <script>
        /* 
            赋值运算符：
                赋值运算符用来将一个值赋值给变量。
                +=
                -=
                /=
                *=
                %=
                **=
                ??=     空赋值 只有当变量为null或undefined才会成功。

        */
       let  a = 5,e
            b = a;
            console.log(b)  //b=5    
            b++;
            c=b
            console.log(b); // 6
            console.log(c)  //6
            c *=b    
             console.log(c)  // 36
            c++;        
             console.log(c) // 37
            e??=c       
        console.log(e)  //37
    </script>
</head>
<body>
    
</body>
</html>